Chiral Isocamphoric Acid: Founding a Large Family of Homochiral Porous Materials

Abstract

Homochiral metal-organic frameworks (MOFs) are an important class of chiral solids with potential applications in chiral recognition; however, relatively few are available. Of great importance is the availability of low-cost, racemization-resistant, and versatile enantiopure building blocks. Among chiral building blocks, d-camphoric acid is highly prolific, yet, its trans-isomer, l-isocamphoric acid, has remained unknown in the entire field of solid-state materials. Its rich yet totally untapped synthetic and structural chemistry has now been investigated through the synthesis of a large family of homochiral metal isocamphorates. The first observation of diastereoisomerism in isostructural MOFs is presented. Isocamphorate has a powerful ability to create framework topologies unexpected from common inorganic building blocks, and isocamphoric acid should allow access to hundreds of new homochiral materials.

Keywords: camphoric acid; chiral ligands; homochiral porous materials; isocamphoric acid; metal-organic frameworks.